diff --git a/test/functional/test-framework b/test/functional/test-framework
index 308b014..b36c34a 160000
--- a/test/functional/test-framework
+++ b/test/functional/test-framework
@@ -1 +1 @@
-Subproject commit 308b014e2b6f7b9eaac6217270d6c9f6b7d4e208
+Subproject commit b36c34a2feca33556c6b871b9d99bde6fb0390a1
diff --git a/test/functional/tests/lazy_writes/test_wb_throttling.py b/test/functional/tests/lazy_writes/test_wb_throttling.py
index 5bee36a..80cbfe3 100644
--- a/test/functional/tests/lazy_writes/test_wb_throttling.py
+++ b/test/functional/tests/lazy_writes/test_wb_throttling.py
@@ -14,7 +14,7 @@ from storage_devices.disk import DiskType, DiskTypeSet, DiskTypeLowerThan
 from test_tools import fs_utils
 from test_tools.fio.fio import Fio
 from test_tools.fio.fio_param import ReadWrite, IoEngine
-from test_tools.iostat import IOstat
+from test_tools.iostat import IOstatExtended
 from test_utils.os_utils import (
     kill_all_io,
     set_wbt_lat,
@@ -100,10 +100,10 @@ def test_wb_throttling():
         eta = runtime
         while eta.total_seconds() > 0:
             # Instead of explicit sleeping with `time.sleep()` iostat is used for waiting
-            iostat = IOstat.get_iostat_list(
+            iostat = IOstatExtended.get_iostat_list(
                 [core, cache_device, core_device],
                 since_boot=False,
-                interval=sleep_interval.total_seconds(),
+                interval=int(sleep_interval.total_seconds()),
             )
             TestRun.LOGGER.debug(f"{iostat}")
             eta -= sleep_interval